... NGC 1850: Gas Clouds and Star Clusters . ... Summer at the South Pole . ... The December solstice brings the beginning of Winter to Earth's Northern Hemisphere and Summer time to the South! ... Simulated Supergiant Star . ... Consider this "star in a box". Of course, the box is actually a computational box consisting of a three dimensional grid of points, and the star is a virtual one whose physical properties and internal dynamics are numerically simulated at the points on the grid. ...

... 2000 December 24 . NGC 1850: Gas Clouds and Star Clusters . ... Globular clusters as young as NGC 1850 don't exist here. ... Below and right of the main group of stars known as NGC 1850 A is a smaller, still younger group dubbed NGC 1850B . This cluster is made of stars only about four million years old. The large red cloud of gas surrounding the clusters may have been predominantly created by supernovae explosions of stars in the younger cluster. ... About APOD | ...

... Tonight's Sky . ... The Magazine . News . Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Open cluster NGC 2818, spiral galaxy NGC 2964, and spiral galaxy NGC 2976 . ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

... Harald Ebeling, University of Hawaii . A Snapshot Survey of The Most Massive Clusters of Galaxies . Abstract . ... Stephan McCandliss, The Johns Hopkins University . ... HST Imaging of UV emission in Quiescent Early-type Galaxies . ... Distances to Eclipsing M Dwarf Binaries . ... SL2S: The Strong Lensing Legacy Survey . ... Hubble Investigation of Asteroid 21 Lutetia in Support of the Rosetta Mission Flyby . ... GO 11289: SL2S - The Strong Lensing Legacy Survey . ... Past weeks: . ...

... December 13, 1997 . The Coma Cluster of Galaxies . ... The Coma Cluster of Galaxies pictured is one of the densest clusters known - it contains thousands of galaxies . Each of these galaxies house billions of stars - just as our own Milky Way Galaxy does. ... In fact, the Coma Cluster is so big it takes light millions of years just to go from one side to the other! Most galaxies in Coma and other clusters are ellipticals , while most galaxies outside of clusters are spirals . ...

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

... Calendar . ... I n the last day of the International Year of Astronomy ( early evening of 31 December 2009), the Moon had the smallest partial eclipse that we have seen in Ireland and the UK for 40 years: the Moon was 8% covered by the Earth's shadow. Incidentally, this was also a "Blue Moon" - the name given for the second full Moon within a calendar month. ... International Year of Astronomy, Ireland National Node . ...

Astronotes Armagh Planetarium's Stellar Blog! ... Milky Way . Stars . ... This dramatic image depicts Omega Centauri, one of 200 or so globular clusters orbiting our Milky Way galaxy. ... Swarms of tightly packed stars, numbering in the thousands to low millions, globular clusters are cosmic fossils, relics of the early times of our galaxy. Omega Centauri may actually be the core of a smaller galaxy ripped apart and assimilated by our own Milky Way in the distant past. ...

A Canadian and American team of Astronomers have used the 305-m wide Arecibo radio dish, the world's largest and most sensitive radio telescope, to uncover a dozen new super-fast-spinning pulsars. The team directed their search for these rare and exotic stars by pointing the Arecibo radio telescope towards massive star clusters, called Globular Clusters, orbiting our Milky Way galaxy. ... One of the most exotic residents in the Globular cluster system are the millisecond pulsars. ...

... The highlight of the month is the total eclipse of the Moon during the night of December 20/21. ... Listed below are some of the key events, and the times they will occur, during December's total lunar eclipse. ... The eclipse is also visible in its entirety from Alaska (local time is UT тАУ 9 hours) and Hawaii (UT тАУ 10 hours), but be aware that most of the eclipse occurs on the 20th in these two regions. ... Penumbral Eclipse Begins . ... Partial Eclipse Begins . ... Total Eclipse Begins . ...

This animation shows a galaxy cluster with two mass concentrations (the pink shading indicates the projected mass density) lensing a background field of faint blue galaxies. ... Inside the Einstein ring radius one has radial arcs, and right in the center of the cluster there are demagnified images. The highest magnifications occur at the Einstein ring radius, giving the large tangential arcs. ... Abell 2218 and CL2244-02 are clusters with tangential arcs. ... Tutorial : Part 1 | Part 2 | ...

... Structure of Data . ... Catalog . ... In SAI OCL Catalog, we introduce our work on investigation of the Milky Way system of open star clusters. The main goal of our study is a search for new clusters using huge surveys. 168 new clusters have been already discovered by us using J,H,Ks data from 2MASS point source catalog. ... For 141 new clusters, we found their physical parameters using J,H,Ks data from 2MASS catalog and, for a number of clusters, our UBVRI CCD observational magnitudes. ...

... Bringing news from across the Universe to children all around the world . ... Smoking, drinking alcohol and eating bad food can make you look years older and live years less. It turns out that the same is true for star clusters! Globular clusters, like the one in this space photograph, are groups of stars tightly bundled together by gravity. ... Now astronomers have come across something very strange hidden deep in the hearts of these giant old star cities: young stars! ...

ECLIPSES, TRANSITS OF MERCURY AND VENUS . Year 1999 . Year 2000 . Year 2001 . Year 2002 . Year 2003 . Year 2004 . Year 2005 . ... Total solar eclipse . ... Transit of Mercury across the solar disk . ... Total lunar eclipse . ... Partial solar eclipse . ... Partial lunar eclipse . ... Annular solar eclipse . ... Penumbral lunar eclipse . ... big map . ... Transit of Venus across the solar disk . ... Annular-total solar eclipse . ... Non-central annular solar eclipse . ...

... Bad Astronomy . ... Bitesize Astronomy . ... The next step up are true clusters, called open clusters . Open clusters (sometimes misleadingly called "galactic clusters") are groups of stars ranging in size from a few dozen stars up to tens of thousands. ... The youngest is about 1 or 2 million years old, while the oldest is about 6 or 7 billion years, making it just older than our own solar system. ... So by looking at the stars in the cluster we can tell pretty well how old they are. ...

... galaxies: bulges galaxies: clusters: general galaxies: clusters: individual: . ... star formation statistics stellar content structure Cosmology ( cosmology :) cosmic background radiation ( cosmology :) cosmological parameters cosmology : miscellaneous cosmology : observations cosmology : theory ( cosmology :) dark ages, reionization, first stars ( cosmology :) dark energy ( cosmology :) dark matter ( cosmology :) diffuse radiation ( cosmology :) distance scale ( cosmology :) early Universe (...

... Eclipses of the Moon in 2009 : . In 2009 there are four eclipses of the Moon (tree penumbral eclipses on February 9, July 7, and August 5-6 and a partial eclipse on December 31). ... Moon enters penumbra (P 1 ) . ... Moon leaves penumbra (P 4 ) . ... Eclipse, lunar : . ... It may be total (the Moon passing completely through the Earth's umbra ), partial (the Moon passing partially through the Earth's umbra at maximum eclipse), or penumbral (the Moon passing only through the Earth's penumbra ). ...

... We address a question if globular clusters (GC) in a protogalaxy could for some time evolve chemically as isolated systems, enriching themselves with heavy elements produced in first supernova events that follow initial star formation. We determine both the critical mass of a protoglobular cluster that is needed to retain the ejecta of the very first supernova, and the critical energy (i.e., number of supernovae) that is needed to expel the residual gas from a cluster of a given mass. ...

... Posts tagged ?Globular Clusters? Oct 26th, 2007| 06:52 pm | ... I hope there are a paper or two drags your attentions and stimulates your thoughts in astrostatistics from arXiv. ... ArXiv] 4th week, Oct. ... Tags: Astrometry , Bayesian , Change Point , Globular Clusters , Matching , X-ray Binaries . ... This week, instead of only filtering AstroStatistics related papers from arxiv, I chose additional arxiv/astro-ph papers related to CHASC folks? astrophysical projects. ... ArXiv] 1st week, Oct. ...

... Galactocentric distance dependences of the physical parameters of globular clusters. ... The straight line in (a) is the rms regression. The large circles in (b) show mean masses within narrow R intervals, and the solid lines show the rms regression fits for thick-disk and old-halo (left) and young-halo and corona (right) clusters. The dashed lines in (c) and (d) are upper and lower envelopes drawn by eye. discussion in the text | privious figure | next figure . ...